| 1. |
- Nylén, Anders, et al.
(author)
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Control Design Based on FMI: A Diesel Engine Control Case Study
- 2016
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In: 8th IFAC Symposium on Advances in Automotive Control AAC 2016. - : Elsevier BV. ; 49:11, s. 231-238
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Conference paper (peer-reviewed)abstract
- Modelica allows systems to be described with reuseable components and with a high precision. To be able to use such complex models efficiently, high demands are set on tools that allow the user to extract the information needed from the models in a straight-forward manner. For this purpose, design-of-experiments techniques can be used to systematically analyze the complex models.In this paper, it is demonstrated how a Modelica model of a diesel engine can be used for control design. The engine model has multiple inputs and outputs, it is nonlinear, has many parameters, and has a higher order than most control design algorithms are able to handle in a numerically robust way.It is shown how the features for dynamic design-of-experiments analysis in the FMI Toolbox for MATLAB can be used to analyze the variation in system dynamics across the engine operating range. A gain scheduling of nine multivariable linear-quadratic-gaussian (LQG) controllers, is designed based on linearization and model reduction of the original nonlinear FMU model.
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| 2. |
- Bomphrey, Richard J., et al.
(author)
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Flight of the dragonflies and damselflies
- 2016
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In: Philosophical Transactions of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 371:1704
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Journal article (peer-reviewed)abstract
- This work is a synthesis of our current understanding of the mechanics, aerodynamics and visuallymediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparative flight performance and pursuit strategies during predatory and territorial flights. Newdata are set in context by brief reviews covering anatomy at several scales, insect aerodynamics, neuromechanics and behaviour. We achieve a new perspective by means of a diverse range of techniques, including laser-line mapping of wing topographies, computational fluid dynamics simulations of finely detailed wing geometries, quantitative imaging using particle image velocimetry of on-wing and wake flow patterns, classical aerodynamic theory, photography in the field, infrared motion capture and multi-camera optical tracking of free flight trajectories in laboratory environments. Our comprehensive approach enables a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, through the aeromechanical interface with the surrounding fluid, to flight performance under cruising and higher-energy behavioural modes.
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| 3. |
- Christoffer Johansson, L., et al.
(author)
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Mechanical power curve measured in the wake of pied flycatchers indicates modulation of parasite power across flight speeds
- 2018
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In: Journal of the Royal Society Interface. - : The Royal Society. - 1742-5689 .- 1742-5662. ; 15:138
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Journal article (peer-reviewed)abstract
- How aerodynamic power required for animal flight varies with flight speed determines optimal speeds during foraging and migratory flight. Despite its relevance, aerodynamic power provides an elusive quantity to measure directly in animal flight. Here, we determine the aerodynamic power from wake velocity fields, measured using tomographical particle image velocimetry, of pied flycatchers flying freely in a wind tunnel. We find a shallow U-shaped power curve, which is flatter than expected by theory. Based on how the birds vary body angle with speed, we speculate that the shallow curve results from increased body drag coefficient and body frontal area at lower flight speeds. Including modulation of body drag in the model results in a more reasonable fit with data than the traditional model. From the wake structure, we also find a single starting vortex generated from the two wings during the downstroke across flight speeds (1–9 m s21). This is accomplished by the arm wings interacting at the beginning of the downstroke, generating a unified starting vortex above the body of the bird. We interpret this as a mechanism resulting in a rather uniform downwash and low induced power, which can help explain the higher aerodynamic performance in birds compared with bats.
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| 4. |
- Fagrell, Per, et al.
(author)
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Affiliated Faculty as a strategic resource: Industry and university expectations
- 2015
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Conference paper (peer-reviewed)abstract
- IntroductionThe entire system of higher education has changed radically during the last decades. This includes for example both changes in the structure of funding as well as increased demands from the labour market. One strategy to adopt to the new conditions is to develop close ties to external organizations such as industry (Clark 1998; Slaughter and Leslie 1997). This paper investigates expectations on, and roles of, researchers from industry, affiliated part time at Higher Education Institutions (HEIs). In this paper we call these researchers “affiliated faculty”. The questions are, what are the expectations from HEIs as well as from industry on the affiliated faculty? And how does this correspond to the role taken by these affiliated researchers?MethodologyThe paper is based on the results of documentary studies and interviews at KTH Royal Institute of Technology and Mälardalen University. In total 27 interviews, including affiliated professors and management from industry and HEI, are undertaken. From this material, a pattern has been distinguished through content analysis (Patton 2002).Preliminary ResultsThe interviews reveal that high but divergent expectations are placed on the affiliated faculty. Affiliated faculty are expected to bring in new experiences and contacts from industry to enrich the university environment. However the process of affiliating a professor is described as very dependent on personal contacts. The affiliated faculty are also a way of promoting the university, making its research and its brand more visible outside academia. By contrast, industry has its primary focus on educational aspects. Industrial partners are, for example, interested in bringing concrete industrial problems that can be used as examples in teaching and learning. Affiliated professors themselves express that one of their missions is to identify the best students for future recruitment. From a personal perspective, the affiliated professors appreciate the possibility of having the time to go deeper into questions that they do not find time for in their ordinary jobs.
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| 5. |
- Henningsson, Anna, et al.
(author)
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Human tick-borne encephalitis and characterization of virus from biting tick
- 2016
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In: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 22:8, s. 1485-1487
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Journal article (peer-reviewed)abstract
- We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity. © 2016, Centers for Disease Control and Prevention (CDC). All rights reserved.
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| 6. |
- Henningsson, Anna, et al.
(author)
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Low risk of seroconversion or clinical disease in humans after a bite by an Anaplasma phagocytophilum-infected tick
- 2015
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In: Ticks and Tick-borne Diseases. - : Elsevier. - 1877-959X .- 1877-9603. ; 6:6, s. 787-792
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Journal article (peer-reviewed)abstract
- The risk of contracting human granulocytic anaplasmosis (HGA) after a tick bite is mainly unknown. In this study we investigated the clinical and serological response in 30 humans bitten by ticks positive for Anaplasma phagocytophilum (Group A), 30 humans bitten by Borrelia burgdorferi sensu lato (s.l.)-positive ticks (Group B), and 30 humans bitten by ticks negative for both A. phagocytophilum and B. burgdorferi s.l. (Group C). Ticks, blood samples and questionnaires were collected from tick-bitten humans at 34 primary healthcare centres in Sweden and in the Åland Islands, Finland, at the time of the tick bite and after three months. A total of 2553 ticks detached from humans in 2007-2009 were analyzed by polymerase chain reaction, and 31 (1.2%) were positive for A. phagocytophilum, 556 (21.8%) were positive for B. burgdorferi s.l., and eight (0.3%) were co-infected by A. phagocytophilum and B. burgdorferi s.l. The overall prevalence of Anaplasma IgG antibodies in the included participants (n=90) was 17%, and there was no significant difference between the groups A-C. Only one of the participants (in Group C) showed a four-fold increase of IgG antibodies against A. phagocytophilum at the three-month follow-up, but reported no symptoms. The frequency of reported symptoms did not differ between groups A-C, and was unrelated to the findings of A. phagocytophilum and B. burgdorferi s.l. in the detached ticks. We conclude that the risk for HGA or asymptomatic seroconversion after a tick bite in Sweden or in the Åland Islands is low, even if the tick is infected by A. phagocytophilum.
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| 7. |
- Henningsson, Marianne, 1950-, et al.
(author)
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Perceived landscape values and public participation in a road-planning process - a case study in Sweden
- 2015
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In: Journal of Environmental Planning and Management. - : Informa UK Limited. - 0964-0568 .- 1360-0559. ; 58:4, s. 631-653
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Journal article (peer-reviewed)abstract
- The European Landscape Convention indicates that assessment of different dimensions that exist in landscapes should be taken into account in planning. In this study, we first investigated ecological, cultural and social values as perceived by the local people in a highway-planning process in Sweden. Next, we explored which factors influenced the local people's participation in the road-planning process. We used questionnaires, planning documents and the Theory of Planned Behavior to investigate the relations between different factors and local people's participation in the planning process. The results showed that people presumed the ecological values in the landscape to be adversely affected by the new road, while the social values would remain the same. Landowners had heard of the participatory-process, but few participated. Those who lived within 300m of the road were more active in the planning process than people living further away. The findings suggest that people living within a few hundred metres of the road should be treated as key stakeholders in the planning process. The involvement of other stakeholders, and when in the public participation process stakeholders should be involved, is also discussed.
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| 8. |
- Henningsson, Per, et al.
(author)
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Aerodynamics of manoeuvring flight in brown long-eared bats (Plecotus auritus)
- 2018
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In: Journal of the Royal Society, Interface. - : The Royal Society. - 1742-5662 .- 1742-5689. ; 15:148
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Journal article (peer-reviewed)abstract
- In this study, we explicitly examine the aerodynamics of manoeuvring flight in animals. We studied brown long-eared bats flying in a wind tunnel while performing basic sideways manoeuvres. We used particle image velocimetry in combination with high-speed filming to link aerodynamics and kinematics to understand the mechanistic basis of manoeuvres. We predicted that the bats would primarily use the downstroke to generate the asymmetries for the manoeuvre since it has been shown previously that the majority of forces are generated during this phase of the wingbeat. We found instead that the bats more often used the upstroke than they used the downstroke for this. We also found that the bats used both drag/thrust-based and lift-based asymmetries to perform the manoeuvre and that they even frequently switch between these within the course of a manoeuvre. We conclude that the bats used three main modes: lift asymmetries during downstroke, thrust/drag asymmetries during downstroke and thrust/drag asymmetries during upstroke. For future studies, we hypothesize that lift asymmetries are used for fast turns and thrust/drag for slow turns and that the choice between up- and downstroke depends on the timing of when the bat needs to generate asymmetries.
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| 9. |
- Henningsson, Per, et al.
(author)
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The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.
- 2015
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In: Journal of the Royal Society Interface. - : The Royal Society. - 1742-5662 .- 1742-5689. ; 12:108
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Journal article (peer-reviewed)abstract
- Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.
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| 10. |
- Lager, Malin, et al.
(author)
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Molecular detection of Borrelia burgdorferi sensu lato - An analytical comparison of real-time PCR protocols from five different Scandinavian laboratories
- 2017
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In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:9
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Journal article (peer-reviewed)abstract
- Introduction Lyme borreliosis (LB) is the most common tick transmitted disease in Europe. The diagnosis of LB today is based on the patient A s medical history, clinical presentation and laboratory findings. The laboratory diagnostics are mainly based on antibody detection, but in certain conditions molecular detection by polymerase chain reaction (PCR) may serve as a complement. Aim The purpose of this study was to evaluate the analytical sensitivity, analytical specificity and concordance of eight different real-time PCR methods at five laboratories in Sweden, Norway and Denmark. Method Each participating laboratory was asked to analyse three different sets of samples (reference panels; all blinded) i) cDNA extracted and transcribed from water spiked with cultured Borrelia strains, ii) cerebrospinal fluid spiked with cultured Borrelia strains, and iii) DNA dilution series extracted from cultured Borrelia and relapsing fever strains. The results and the method descriptions of each laboratory were systematically evaluated. Results and conclusions The analytical sensitivities and the concordance between the eight protocols were in general high. The concordance was especially high between the protocols using 16S rRNA as the target gene, however, this concordance was mainly related to cDNA as the type of template. When comparing cDNA and DNA as the type of template the analytical sensitivity was in general higher for the protocols using DNA as template regardless of the use of target gene. The analytical specificity for all eight protocols was high. However, some protocols were not able to detect Borrelia spielmanii, Borrelia lusitaniae or Borrelia japonica.
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